Pressure gauge

ABSTRACT

A combined gauge and inflator for a tire includes a support member threaded on the tire stem with a body slidably disposed within the support member and locked in a first position. The body has a passage extending therethrough with a spring-biased piston slidably disposed therein. With the body in the first position, the piston rests against a spring-biased plunger, which opens the valve in the tire stem when the plunger spring is overcome. The plunger spring is overcome either by an air chuck acting on the piston to move the piston against the plunger or when the body is moved from its first position to a second position in which the body engages the plunger. When the body is moved against the plunger, sealing means on the piston seal the body passage so that air pressure in the tire moves the piston relative to the body. A scale on the piston cooperates with a marker on the body to indicate the pressure of the tire.

United States Patent [72] Inventors Billy Lynn Guy 240 Shady Lane,Lexington, Ky. 40503; Walden Sam Campbell, 1013 Celia Drive, Lexington,Ky. 40504 [21] Appl. No. 846,518 [22] Filed July 31, 1969 [45] PatentedJuly 13, 1971 [54] PRESSURE GAUGE 20 Claims, 5 Drawing Figs.

[52] US. Cl 137/227, 73/1463, 116/34, 137/557, 152/429 [51] lnt.Cl.F161: 15/20 [50] Field of Search 137/227; 73/1468; 116/34; 152/429 [56]References Cited UNITED STATES PATENTS 1,276,089 8/1918 Loomis 137/2271,482,237 1/1924 Lent 137/227 Primary Examiner-Harold W WeakleyArtorney-Frank C. Leach, Jr

ABSTRACT: A combined gauge and inflator for a tire includes a supportmember threaded on the tire stem with a body slidably disposed withinthe support member and locked in a first position. The body has apassage extending therethrough with a spring-biased piston slidablydisposed therein. With the body in the first position, the piston restsagainst a spring-biased plunger, which opens the valve in the tire stemwhen the plunger spring is overcome. The plunger spring is overcomeeither by an air chuck acting on the piston to move the piston againstthe plunger or when the body is moved from its first position to asecond position in which the body engages the plunger. When the body ismoved against the plunger, sealing means on the piston seal the bodypassage so that air pressure in the tire moves the piston relative tothe body. A scale on the piston cooperates with a marker on the body toindicate the pressure of the tire.

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A A R 77/ /1 A 317 ATTORNEY PRESSURE GAUGE To obtain a consistentreading of the pressure of 9 tire, tire manufacturers recommend that thepressure of the tire be ascertained when the tire is cool. it is theirrecommendation that the tire not be run over a mile before the pressureof the tire is determined. Otherwise, the heat generated by the runningtire causes the pressure in the tire to increase.

Accordingly, since most motorists do not live sufficiently close to aservice station to be able to drive to the service station without thetires becoming heated, most automobile owners are unable to obtain aconsistent reading of the pressure in the tires of their automobilesduring their visits to the service station. Some motorists seek toalleviate this problem by purchasing a tire pressure gauge with whichthey check each of the tires. However, this necessitates the gauge beingproperly positioned on the tire stem to prevent any significant loss oftire pressure. As a result, the users of these gauges may bleed some ofthe air in the tire during a reading thereof. Furthermore, the gauge canbe misplaced or lost.

If a motorist does not own a pressure gauge, the service stationattendant is usually requested to check the pressure of the tires.However, the activity at the service station may preclude one fromasking the attendant to check the tires with any regularity. As aresult, the tires may become underinflated and wear before it isdetermined that air should be added.

Since many cars are equipped with power steering rather than mechanicalsteering, it is not as easy to detect} underinflated tires Therefore, amotorist cannot rely upon the feel the tire through the steering butmustfrequently check the pressure of each of his tires to ascertainwhether the tire is properly inflated.

Furthermore, since tire pressure gauges are all not calibrated to thesame accuracy and all do not retain their accuracy, the tires may beeither overinflated or unden'nflated after each checking of the pressureof the tires and the addition or removal of air therefrom as a resultthereof. Additionally, as previously mentioned, the pressure in the tirevaries in accordance with the amount of heat that has been generated inthe tire during use before the air pressure of the tire is ascertained.

Thus, if a tire is not properly inflated, full advantage of its intendedpurpose is not achieved. This is particularly true of the new radialtires.

Additionally, proper inflation of the tire saves its sidewall andresults in a longer life. Thus, a properly inflated tire produces moremiles of use, particularly when used on freeways at high speeds, andreduces the owner's expense for replacement.

When hitting an object such as a curb, a rock, or the like, a properlyinflated tire is not bruised or split as easily as a tire that is notproperly inflated. Thus, proper inflation of-the tire can preventaccidents as well as damage to the tire.

The present invention satisfactorily overcomes the foregoing problems byproviding a tire gauge that may be attached to the tire stem. in thepresent invention, it is only necessary for the automobile owner totwist a body and slide it slightly relative to a support member todetermine the air pressure of the tire. During this movement of thebody, the valve in the tire stem is opened to allow the pressure of theair to act on a pressure-responsive member, which has indicating meansthereon and is slidably disposed in the body. The amount of air releasedby the preset invention during reading is very small so that a number ofreadings of the tire presure by the gauge of the present invention willnot cause any significant amount of air to be bled from the tire. As aresult, the tire will not become underinflated due to a number ofreadings when using the gauge of the present invention.

Furthermore, the tire gauge of the present invention is constructed topermit the tire to be inflated without removal of the tire gauge fromthe tire stern. Thus, the present invention provides a combined tirepressure gauge and inflator.

By using the combined tire pressure gauge and inflator of the presentinvention, the user has the convenience of always being able to quicklyand accurately ascertain the pressure of a tire. Therefore, bydetermining that the tire is properly inflated, the safety of themotorist is increased. Additionally, through maintaining the tire at aproper pressure, savings resulting from increased wear of the tire areprovided by employing the present invention.

It has previously been suggested to utilize a combined-pressure gaugeand inflator for a tire. One previously suggested device is that shownin U.S. Pat. No. 1,300,534 to West. How ever, the aforesaid West patentrequires the release of a coupling sleeve from the tire stem before any.reading of the pressure of the tire is ascertained. Thus, the presentinvention provides a much simpler arrangement for ascertaining thepressure of the tire.

In the aforesaid West patent, there is no sealing means between thepressure-responsive element and the member on which it slides. As aresult, a true air pressure is not necessarily obtainable when utilizingthe gauge of the aforesaid West patent. In the present invention, thepressure-responsive member, which is slidably disposed in a passagein-the body that is slidably disposed on the support member, seals thepassage to prevent any leakage of the air from the tire when thepressure of the tire is ascertained.

In the aforesaid West patent, it is necessary to employ a cap to close apassage through which air is supplied to the tire when the tire is to beinflated. Since there is no sealing arrangement provided between the capand the support body, the possibility exists that there may be leakageof the air pressure in this manner when the air pressure of the tire isbeing ascertained.

As previously mentioned, the sealing means on pressureresponsive memberof the present invention insures that there is no leakage through thepassage in the body. As a result, it is not necessary to utilize anytype of a cap with the combined pressure gauge and inflator of thepresent invention.

Another combined pressure gauge and tire inflator is shown in U.S. Pat.No. 1,422,256 to Conrad et al. In the aforesaid Conrad et al. patent, itis necessary to employ a check valve in the combined gauge and inflator.Thus, it is necessary to open both this check valve and the valve in thetire stem to inflate the tire. Furthermore, this check valve must berelied upon to seal the passage from the exterior of the body to thetire. The device of the aforesaid Conrad et al. patent also employs aninflator bag as its pressure-responsive member.

The present invention is a much simpler and less expensive device thanthat of the aforesaid Conrad et al. patent. Thus, the present inventiondoes not require any additional valve structure other than the valve inthe tire stem. Furthermore, a simple pressure-responsive member isemployed rather than the complicated arrangement of the aforesaid Conradet al. patent in which an inflator bag is employed.

in the present invention, the valve in the tire stem is never openedexcept when the tire is to be inflated or when the air pressure of thetire is to be ascertained. When the latter occurs, there is a sealbetween the pressure-responsive member, which slides in the passage inthe body, and the body to effectively prevent leakage of any significantamount of the air from the tire.

The seal is mounted so that it is free at all times except when thepressure of the tire is being ascertained. This prevents wear on theseal and buildup of breakout friction.

An object of this invention is to provide a single device for mountingon a tire that allows the pressure of a tire to be determined and thetire to be inflated.

Another object of this invention is to provide a uniqueconstruction fora pressure gauge for ascertaining the air pressure of a tire.

Other objects of this invention will be readily perceived from thefollowing description, claims, and drawing.

This invention relates to a combined tire gouge and inflator formounting on a tire including a support member for mounting on a tirestem with a body supported by the support member for movement betweenfirst and second positions. The body and the support member cooperate toform a chamber therebetween when the body, which has a passage extendingtherethrough to provide communication from the exterior of the body tothe chamber, is in its first position. The support member supportsmeans, which opens the valve in the tire stem and is urged to aninactive position by suitable means. Means is slidably disposed in thepassage in the body and in engagement with the valve opening means whenthe body is in its first position. The slidably disposed means isresponsive to the air pressure in the tire when the body is moved to itssecond position to move the valve opening means to a valve openingposition to open the valve in the tire stem.

At least one of the slidably disposed means and the body has sealingmeans to prevent flow of air through the passage when the body is in itsdisposed position with the sealing means being ineffective when the bodyis in its first position. Means indicates the air pressure of the tirein accordance with the position of the slidably disposed means when thebody is in its second position. The slidably disposed means is movableby an air chuck or the like to more the valve-opening means to avalve-opening position when the body is in its first position to allowair to be supplied from the air chuck through the body passage to thechamber and from the chamber to the tire.

This invention also relates to a pressure gauge for indicating the fluidpressure in an enclosed chamber in which the gauge includes a supportmember for connection to the enclosed chamber with a body supported bythe support member for movement relative thereto between first andsecond positions. The support member supports means, which opens a valvethat controls communication to the enclosed chamber and is urged to aninactive position by suitable means. The body overcomes the urging meansto more the valve-opening means to an active position when the body ismoved from its first position to its second position. The body supportsmeans, which is responsive to the pressure of the enclosed chamber whenthe valve-opening means is in its active position. At least one of theresponsive means and the body has means to indicate the pressure of thefluid within the enclosed chamber in accordance with the position of theresponsive means in the body.

This invention further relates to a pressure gauge for indicating thefluid pressure in an enclosed chamber in which the gauge includes asupport member for connection to the enclosed chamber with a bodysupported by the support member for movement relative thereto betweenfirst and second positions. The body, which has a passage extendingtherethrough, opens a valve that controls communication to the enclosedchamber when the body is in its second position. Means, which isslidably disposed in the body passage, is responsive to the fluidpressure in the enclosed chamber when the body is in its secondposition. At least one of the slidably disposed means and the body hasmeans to seal the body passage only when the body is in its secondposition. The gauge also has means to indicate the fluid pressure in theenclosed chamber in accordance with the position of the slidablydisposed means in the body.

The attached drawing illustrates a preferred embodiment of theinvention, in which: 7

FIG. 1 is a vertical sectional view of the combined gauge and inflatorof the present invention in its inactive or stow position in which thereis neither inflating of the tire nor ascertaining of the tire pressure;

FIG. 2 is a vertical sectional view, similar to FIG. 1, but showing theposition of the elements of the combined gauge and inflator when thetire is being inflated;

FIG. 3 is a vertical sectional view, similar to FIG. 1, but showing theposition of the elements of the device of the present invention when thepressure of the tire is being ascertained;

FIG. 4 is an elevational view of a portion of the body of the device ofthe present invention; and

FIG. 5 is an elevational view ofa seal used with the device of thepresent invention. 7

Referring to the drawing and particularly FIG. 1, there is shown a stem10 ofa tire having a valve 12 mounted therein in the well-known manner.When the valve 12 is depressed, communication with the interior of thetire is achieved whereby either air may be bled from the tire or thetire may be inflated.

The combined pressure gauge and inflator of the present inventionincludes a support member 14 which is supported on the tire stem 10 fordisposition in a fixed position. A lower hollow cylindrical portion 15of the support member 14 has threads on its inner surface forcooperation with threads 16 on the tire stem 10. Thus, when the portion15 is threaded on the threads 16 of the stem 10 as shown in FIG. 1, thesupport member 14 is fixed to the tire stem 10.

The support member 14 has a body 17 slidably disposed in its upperhollow cylindrical portion 18. The body 17 has a pair of grooves 19 and20 in its outer surface and diametrically disposed to each other. Asshown in FIG. 4, the groove 19 includes a first straight portion 21 anda second retaining portion 22. The groove 20 is similarly formed.

The groove 19 has a ball 23 disposed therein, and the groove 20 has aball 24 disposed therein. The ball 23 partially extends through acircular-shaped opening 25 in the hollow cylindrical portion 18 of themember 14 while the ball 24 partially extends through a circular-shapedopening 26 in the hollow cylindrical portion 18 of the support member14. The openings 25 and 26 are diametrically disposed to each other andare larger than the balls 23 and 24 to allow insertion of the balls 23and 24 into the grooves 19 and 20.

A retaining ring 27 fits over a bead 28 on the upper end of the supportmember 14. The retaining ring 27 has its lower surface formed tocooperate with the balls 23 and 24, as shown in FIG. 1, to retain themwithin the grooves 19 and 20.

When the body 17 is disposed in its inactive or stow position as shownin FIG. 1, the ball 23 is disposed in the retaining portion 22 of thegroove 19. Likewise, the ball 24 is disposed in the retaining portion ofthe groove 20. As a result, the body 17 is locked or held in theposition shown in FIG. 1.

The body 17 has a passage 29 extending therethrough to providecommunication from the exterior of the body 17 to a chamber 30, which isformed between the body 17 and the support member 14 when the body 17 isin the position of FIG. 1. A rod 31 of a piston 32 is disposed withinthe passage 29 in sliding relation to the body 17. The rod 31 has asmaller diameter than the passage 29 so as to not interfere withcommunication between the exterior of the body l7 and the chamber 30.

The piston 32 has a pair of vertically spaced flanges 33 and 34, whichhave a larger diameter than the rod 31 but a smaller diameter than thepassage 29, on the rod 31 to mount a sealing ring 35 therebetween. Acoil spring 36 surrounds the rod 31 of the piston 32 and acts againstthe flange 33 of the piston 32 to urge the piston 32 to the position ofFIG. I when the body 17 is in the position in which the balls 23 and 24are in the retaining portions of the grooves 19 and 20, respectively, inthe body 17.

When the body 17 is locked in the position of FIG. 1, the flange 34 ofthe piston 32 engages a plunger 37, which is slidably supported by thesupport member 14 and adapted to move the valve 12 in the tire stem 10to an open position. The plunger 37 includes a baseplate 38 and adownwardly projecting portion 39, which extends through a passage 40 inthe support member 14 and has its lower end adapted to act against thevalve 12 in the tire stem 10.

A coil spring 41 is disposed within the upper hollow cylindrical portion18 of the support member 14 and acts against the lower surface of thebaseplate 38 of the plunger 37 to move it to an inactive position inwhich the downwardly projecting portion 39 of the plunger 37 cannotengage the valve 12 in the tire stem 10. The upward movement of theplunger 37 by the spring 41 is limited by a nut 42 on the lower end ofthe projecting portion 39 of the plunger 37 engaging an annular surface43 of the support member 14.

The force of the spring 41 is stronger than the force of the spring 36so that the plunger 37 is positioned as shown in FIG. 1 wherein the nut42 engages the surface 43 of the support member 14. In this position,the flanges 33 and 34 of the piston 32 are disposed in the chamber 30and exterior of the passage 29 so that the chamber 30 communicates withthe exterior of the body 17 through the passage 29.

In this position, the sealing ring 35 is not in engagement with the wallof the passage 29 so that there is no breakout friction buildup on thesealing ring 35 when it is necessary to move the piston 32 relative tothe boY 17. This arrangement also permits air to be supplied to thechamber 30 from the exterior of the body 17 from an air chuck 44 or thelike.

When the tire 11 is to be inflated, the air chuck 44 is moved intoengagement with the upper end of the body 17 so that an actuatingportion 45 of the air chuck 44 engages the upper end of the piston rod31. As a result, pressurized air is supplied from the air chuck 44 tothe chamber 30 through the passage 29 between the rod 31 of the piston32 and the wall of the passage 29.

Since the body 17 is locked to the supportmember 14 by the balls 23 and24 being disposed in the retaining portions of the grooves 19 and 20,the body 17 cannot move downwardly when the air chuck 44 contacts it.Therefore, when the actuating portion 45 of the air chuck 44 engages theupper end of the piston rod 31, the plunger 37 is moved downwardly sothat the lower end of the downwardly projecting portion 39 engages theupper end of the valve 12 to open it. The pressurized air flows from thechamber 30 and through the passage-40 in the support member 14 and pastthe valve 12 in the tire stem to inflate the tire. Upon removal of theair chuck 44 from engagement with the piston rod 31, the plunger 37 ismoved upwardly by the spring 41 whereby the valve 12 returns to itsclosed position.

When it is desired to ascertain the pressure of theair within the tire,the body 17 is moved downwardly relative to the support member 14 bytwisting the body 17 so that the balls 19 and 20 no longer are retainedwithin the retaining portions of the grooves 23 and 24 in the body 17.Thus, as the body 17 is pushed downwardly, it also rotates relative tothe support member 14 because of the angle of the grooves 19 and 20relative to the axis of the body 17. Therefore, it is necessary to holdthe body 17 in the position of FIG. 3 whenever the air pressure in thetire is to be ascertained.

When the body 17 is moved to the position of FIG. 3, the sealing ring 35of the piston 32 is disposed within the passage 29 of the body 17 toseal the passage 29. As a result, there can be no leakage of air throughthe passage 29 to the exterior of the body 17.

When the body 17 is moved downwardly from the position of FIG. 1 to theposition of FIG. 3, its lower end surface 46 engages the upper surfaceof the baseplate 38 of the plunger 37 to move the downwardly projectingportion 39 into engagement with the valve 12 in the stem 10. This opensthe valve 12 to allow air to flow from the tire through the stem 10, thepassage 40 in the support member 14, and openings 47 in the baseplate 38of the plunger 37 to the passage 29.

As a result, the pressure of the air acts against the sealing ring 35 onthe piston 32 to cause the piston 32 to be responsive to this pressure.The air pressure pushes the piston 32 upwardly through the passage 29against the force of the spring 36 so that a portion of the rod 31 ofthe piston 32 extends exteriorly of the body 17 as shown in FIG. 3.

The rod 31 of the piston 32 has a scale 48, which has indicia calibratedin pounds per square inch, thereon for cooperation with an edge 49 ofthe body 17. The edge 49 functions as a marker for cooperation with theindicia on the scale 48 to indicate the pressure in the tire. The spring36 is selected in accordance with the spacing of the indicia of thescale 48 to oppose the movement of the piston 32 by the pressure in thetire so that the correct reading is obtained by the edge 49 of the body17 being aligned with one of the indicia on the scale 48.

To insure that the pressure of the tire is applied to the piston 32, thebody 17 has a sealing ring 50 thereon for cooperation with the innerwall of the upper hollow cylindrical portion 18 of the support member14. Furthermore, the support member 14 carries a sealing ring 51adjacent the threads on the lower hollow cylindrical portion 15 of thesupport member 14 to form a seal therebetween.

Accordingly, when the body 17 is released by the user and returned tothe position of FIG. 1 by the force of the springs 41 and 36 whereby thevalve 12 in the tire stem 10 closes, air is trapped between the piston32 and the closed valve 12. The pressure of this trapped air could begreater than-the force of the spring 36 so as to prevent the piston 32from returning to the position of FIG. 1 in which the sealing ring 35 isnot within the passage 29.

Accordingly, to avoid the necessity for the user to push down on theupper end of the rod 31 of the piston 32 to return it to the position ofFIG. 1,'the sealing ring 51 has a V-shaped groove 52 (see FIG. 5) in itslower surface to allow this airto be bled. The V-shaped groove 52 is sosmall that there is not leakage of any significant extent during thetime that the pressure of the tire is being determined. While it is nota requisite for satisfactory operation that the sealing ring 51 have theV- shaped groove 52 therein, the V-shaped groove 52 permits the piston32 to return to the position of FIG. 1 without any effort on-the part ofthe user if the pressure of the trapped air is greater than the force ofthe spring 36.

The support member 14, the body 17, and the plunger 37 may be formed ofany suitable material but are preferably formed of a plastic materialsuch as acrylonitrile-butadienestyrene copolymers or polymers, forexample. Two preferred examples of the material of the support member14, the body 17, and the plunger 37 are the ABS plastics, which are soldunder the trade names Cycolac and Tybrene.

By forming the support member 14, the body 17, and the plunger 37 ofplastic, the weight of the combined gauge and inflator of the presentinvention is relatively small. As a result, it does not affect thebalance of the tire to which it is attached. Additionally, the use ofthe plastic substantially reduces the cost.

While the present invention has shown the retaining means for the body17 to be grooves having retaining portions at their lower ends, itshould be understood that any other suitable type of retaining meanscould be employed. For example, the grooves could be replaced byL-shaped grooves receiving pins. In this arrangement, it would benecessary to only rotate the body 17 slightly and then push down so thatthere would be no further rotation of the body 17. However, upon thereturn of the body to the position of FIG. 1, this arrangement wouldnecessitate a spring or other suitable means to urge the pins into theretaining portions of the L-shaped grooves.

While the present invention has shown and described the scale 48 asbeing on the piston rod 31 and the marker being on the body 17, itshould be understood that the body 17 could be formed of a transparentmaterial with the scale thereon and the marker disposed on the pistonrod 31.

Furthermore, the support member 14 could be extended upwardly to have amarker thereon for cooperation with the scale on the piston rod 31 ifdesired. Of course, this also would necessitate the body 17 beingtransparent.

Additionally, with the support member 14 extended upwardly, the scalecould be disposed on the support member 14 and the marker could be onthe piston rod 31. Of course, this would necessitate both the body 17and the support member 14 being transparent.

While the present invention has shown and described the piston 32 ashaving the sealing ring 35 mounted thereon, it should be understood thatsealing means could be mounted on both the body 17 and the piston 32 oronly on the body 17. Of course, in either of these arrangements, thesealing means would be arranged so as to not be effective until the body17 was disposed in the position of FIG. 3.

An advantage of this invention is that the piston seal is effective onlywhen measuring the pressure of the tire whereby the life of the seal isincreased and there is no buildup of breakout friction. Anotheradvantage of this invention is that it is relatively inexpensive. Afurther advantage of this invention is that a single device permits thepressure of the tire to be determined and the tire to be inflated.

For purposes of exemplification, a particular embodiment of theinvention has been shown and described according to the best presentunderstanding thereof. However, it will be apparent that changes andmodifications in the arrangement and construction of the parts thereofmay be resorted to without departing from the spirit and scope of theinvention.

What we claim is:

l. A pressure gauge for indicating the fluid pressure in an enclosedchamber including:

a support member for connection to the enclosed chamber;

a body supported by said support member for movement relative theretobetween first and second positions;

means to open a valve that controls communication to the enclosedchamber, said valve opening means being unconnected to said body andsupported by said support member, said valve opening means being movableindependently of said body;

means urging said valve opening means to an inactive position, saidurging means being supported by said support member;

said body overcoming said urging means to move said valve opening meansto its active position when said body is moved from its first positionto its second position;

means supported by said body and responsive to the fluid pressure of theenclosed chamber when said valve opening means is in its active positionand said body is in its second position;

and at least one of said responsive means and said body having means toindicate the pressure of the fluid within the enclosed chamber inaccordance with the position of said responsive means in said body.

2. The pressure gauge according to claim 1 in which:

said body has a passage extending therethrough and providingcommunication from exterior of said body to the enclosed chamber whensaid valve-opening means is in its active position and said body is inits first position;

said responsive means is slidably disposed in said body passage;

and one of said responsive means and said body has sealing means to sealsaid passage only when said body is in its second position.

3. A pressure gauge for indicating the fluid pressure in an enclosedchamber including a support member for connection to the enclosedchamber;

a body supported by said support member for movement relative theretobetween first and second positions;

said body opening a valve that controls communication to the enclosedchamber, said body opening the valve when said body is in its secondposition;

said body having a passage extending therethrough to providecommunication from exterior of said body to the enclosed chamber whenthe valve is open and said body is in its first position;

means slidably disposed in said body passage and responsive to the fluidpressure in the enclosed chamber when said body is in its secondposition;

at least one of said slidably disposed means and said body having meansto seal said body passage only when said body is in its second positionto prevent flow of fluid pressure from the enclosed chamber through saidpassage to exterior of said body;

and means to indicate the fluid pressure in the enclosed chamber inaccordance with the position of said slidably disposed means in saidbody.

4. The pressure gauge according to claim 3 in which:

said sealing means is mounted only on said slidably disposed means;

and said sealing means is disposed exterior of said passage when saidbody is in its first position.

5. The pressure gauge according to claim 3 in which:

said indicating means includes:

a scale on one of said slidably disposed means and said body;

and marking means on the other of said slidably disposed means and saidbody for cooperation with said scale.

6. A pressure gauge according to claim 3 in which said sealing means ismounted only on said slidably disposed means.

7. A combined tire gauge and inflator for mounting on a tire including:

a support member for mounting on a tire stem;

a body supported by said support member for movement between first andsecond positions;

said body and said support member cooperating to form a chambertherebetween when said body is in its first position;

said body having a passage extending therethrough to providecommunication from exterior of said body to the chamber;

means to open a valve in the tire stem, said valve opening means beingsupported by said support member;

means urging said valve opening means to an inactive positlon;

means slidably disposed in said passage in said body and in engagementwith said valve opening means when said body is in its first position;

said slidably disposed means being responsive to the air pressure in thetire when said body is moved to its second position, said body movingsaid valve-opening means to a valve-opening position to open the valvein the tire stem when said body is in its second position;

at least one of said slidably disposed means and said body havingsealing means to prevent flow of air through said passage when said bodyis in its second position, said sealing means being ineffective whensaid body is in its first position;

means to indicate the airpressure of the tire in accordance with theposition of said slidably disposed means when said body is in its secondposition;

and said slidably disposed means being movable by an air chuck or thelike to move said valve-opening means to a valve-opening position whensaid body is in its first position to allow air to be supplied from theair chuck through said body passage to the chamber and from the chamberto the tire.

8. The combined tire gauge and inflator according to claim 7 includingmeans to lock said body in its first position.

9. The combined tire gauge and inflator according to claim 7 in whichsaid indicating means has means on at least one of said slidablydisposed means and said body.

10. The combined tire gauge and inflator according to claim 7 includingmeans to form a seal between said body and said support member.

11. The combined tire gauge and inflator according to claim 7 in whichsaid sealing means is mounted only on said slidably disposed means.

12. The combined tire gauge and inflator according to claim 11 in whichsaid sealing means is mounted on the portion of said slidably disposedmeans in the chamber when said body is in its first position.

13. The combined tire gauge and inflator according to claim 12 in whichsaid body is supported by said support member for sliding movementbetween its first and second positions.

14. The combined tire gauge and inflator according to claim 13 includingmeans to lock said body in its first position.

15. The combined tire gauge and inflator according to claim 7 in which:

said indicating means includes:

a scale on one of said slidably disposed means and said y; and markingmeans on the other of said slidably disposed means and said body forcooperation with said scale. 16. The combined tire gauge and inflatoraccording to claim 15 in which:

said slidably disposed means has said scale thereon; and said body hassaid marking means thereon.

tion of the tire stem. 1

19. The combined tire gauge and inflator according to claim 7 in whichsaid body is supported by said support member or sliding movementbetween its first and second positions.

20. The combined tire gauge and inflator according to claim 19 includingmeans to lock said body in its first position.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,592,218 Dated Ju1y'1 1971 Inventor-(s) Bllly Lynn y 1 all It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 4, "9" should-read a line 31, after "tires" insert aperiod; line 66, "preset" should read present Column 2, line 65,"buildup" should read build-up line 65, "breakout" should read break outline 74, "gOuge" should read gauge Column 3, line 18, "disposed" shouldread second line 23, "more" should read move lines 23, 24, 35 and 39,cancel the "hyphen each occurrence; line 35, "more" should read moveColumn 4, line 63, "baseplate" should read base plate line 69,"baseplate" should read base plate Column '5, line 9, "breakout" shouldread break out line 10, "buildup" should read build-up line 11, "boY"should read body line 53, "baseplate" should read base plate Column 6,line 75, "buildup" should read build-up Column 7, line 1, "breakout"should read break out line 40, cancel the "hyphen line 48, after"including" insert a colon (:1. Column 8, lines 28, 29, 40 and 41,cancel the "hyphen each occurrence. Column 10, line 3, "or" should readfor Signed and sealed this 30th day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM F'O-1050 (10-69) USCOMM-DC 60376 P09 9 US, GOVERNMENTPRINTING OFFICK: 196D 0-366-33

1. A pressure gauge for indicating the fluid pressure in an enclosedchamber including: a support member for connection to the enclosedchamber; a body supported by said support member for movement relativethereto between first and second positions; means to open a valve thatcontrols communication to the enclosed chamber, said valve opening meansbeing unconnected to said body and supported by said support member,said valve opening means being movable independently of said body; meansurging said valve opening means to an inactive position, said urgingmeans being supported by said support member; said body overcoming saidurging means to move said valve opening means to its active positionwhen said body is moved from its first position to its second position;means supported by said body and responsive to the fluid pressure of theenclosed chamber when said valve opening means is in its active positionand said body is in its second position; and at least one of saidresponsive means and said body having means to indicate the pressure ofthe fluid within the enclosed chamber in accordance with the position ofsaid responsive means in said body.
 2. The pressure gauge according toclaim 1 in which: said body has a passage extending therethrough andproviding communication from exterior of said body to the enclosedchamber when said valve-opening means is in its active position and saidbody is in its first position; said responsive means is slidablydisposed in said body passage; and one of said responsive means and saidbody has sealing means to seal said passage only when said body is inits second position.
 3. A pressure gauge for indicating the fluidpressure in an enclosed chamber including a support member forconnection to the enclosed chamber; a body supported by said supportmember for movement relative thereto between first and second positions;said body opening a valve that controls communication to the enclosedchamber, said body opening the valve when said body is in its secondposition; said body having a passage extending therethrough to providecommunication from exterior of said body to the enclosed chamber whenthe valve is open and said body is in its first position; means slidablydisposed in said body passage and responsive to the fluid pressure inthe enclosed chamber when said body is in its second position; at leastone of said slidably disposed means and said body having means to sealsaid body passage only when said body is in its second position toprevent flow of fluid pressure from the enclosed chamber through saidpassage to exterior of said body; and means to indicate the fluidpressure in the enclosed chamber in accordance with the position of saidslidably disposed means in said body.
 4. The pressure gauge according toclaim 3 in which: said sealing means is mounted only on said slidablydisposed means; and said sealing means is disposed exterior of saidpassage when said body is in its first position.
 5. The pressure gaugeaccording to claim 3 in which: said indicating means includes: a scaleon one of said slidably disposed means and said body; and marking meanson the other of said slidably disposed means and said body forcooperation with said scale.
 6. A pressure gauge according to claim 3 inwhich said sealing means is mounted only on said slidably disposedmeans.
 7. A combined tire gauge and inflator for mounting on a tireincluding: a support member for mounting on a tire stem; a bodysupported by said support member for movement between first and secondpositions; said body and said support member cooperating to form achamber therebetween when said body is in its first position; said bodyhaving a passage extending therethrough to provide communication fromexterior of said body to the chamber; means to open a valve in the tirestem, said valve opening means being supported by said support member;means urging said valve opening means to an inactive position; meansslidably disposed in said passage in said body and in engagement withsaid valve opening means when said body is in its first position; saidslidably disposed means being responsive to the air pressure in the tirewhen said body is moved to its second position, said body moving saidvalve-opening means to a valve-opening position to open the valve in thetire stem when said body is in its second position; at least one of saidslidably disposed meanS and said body having sealing means to preventflow of air through said passage when said body is in its secondposition, said sealing means being ineffective when said body is in itsfirst position; means to indicate the air pressure of the tire inaccordance with the position of said slidably disposed means when saidbody is in its second position; and said slidably disposed means beingmovable by an air chuck or the like to move said valve-opening means toa valve-opening position when said body is in its first position toallow air to be supplied from the air chuck through said body passage tothe chamber and from the chamber to the tire.
 8. The combined tire gaugeand inflator according to claim 7 including means to lock said body inits first position.
 9. The combined tire gauge and inflator according toclaim 7 in which said indicating means has means on at least one of saidslidably disposed means and said body.
 10. The combined tire gauge andinflator according to claim 7 including means to form a seal betweensaid body and said support member.
 11. The combined tire gauge andinflator according to claim 7 in which said sealing means is mountedonly on said slidably disposed means.
 12. The combined tire gauge andinflator according to claim 11 in which said sealing means is mounted onthe portion of said slidably disposed means in the chamber when saidbody is in its first position.
 13. The combined tire gauge and inflatoraccording to claim 12 in which said body is supported by said supportmember for sliding movement between its first and second positions. 14.The combined tire gauge and inflator according to claim 13 includingmeans to lock said body in its first position.
 15. The combined tiregauge and inflator according to claim 7 in which: said indicating meansincludes: a scale on one of said slidably disposed means and said body;and marking means on the other of said slidably disposed means and saidbody for cooperation with said scale.
 16. The combined tire gauge andinflator according to claim 15 in which: said slidably disposed meanshas said scale thereon; and said body has said marking means thereon.17. The combined tire gauge and inflator according to claim 7 in whichsaid support member has an inner threaded portion for cooperation withthe outer threaded portion of the tire stem to mount said support memberon the tire stem.
 18. The combined tire gauge and inflator according toclaim 17 including sealing means carried by said support member to sealsaid support member at the connection of said threaded portion of saidsupport member with the outer threaded portion of the tire stem.
 19. Thecombined tire gauge and inflator according to claim 7 in which said bodyis supported by said support member or sliding movement between itsfirst and second positions.
 20. The combined tire gauge and inflatoraccording to claim 19 including means to lock said body in its firstposition.